The hanking machine of the present invention is intended for cooperation with a wire lead forming machine of the general type disclosed by the copending application of John D. Butler, Ser. No. 235,443, now U.S. Pat. No. 4,370,786 filed Feb. 20, 1981 and by U.S. Pat. No. 4,183,383, both of which have a common assignee herewith. Such a lead forming machine comprises a pair of intermittently moving endless chains with horizontal and parallel top stretches, each chain having cord grippers attached to it at reguarly spaced intervals. At one end of the machine there is mechanism whereby uniform-length cords or leads are cut from a coiled supply of conductor stock of indefinite length. Each such cord is gripped near its opposite ends by a pair of cord grippers, one on each chain, to be held horizontally extended by them and moved transversely to its length past a numer of stations. At some or all of such stations the lead forming machine has mechanisms that operate upon one or both end portions of the cord to prepare it for connection to an electrical appliance. In general, the lead forming machine strips the insulation off of the end portions of the wires that comprise the cord and attaches terminal connectors to at least certain of its end portions, or it otherwise prepares the bared end portions for connection, as by twisting and tinning them. If the leads being made by the machine are intended to serve as power connection cords, the machine will usually cause a wall socket plug to be attached to one end of each cord.
In the past, the leads made by a lead forming machine were simply discharged at its outlet end and where allowed to accumulate until they were carried elsewhere. Where the leads are to be installed as power cords, it is usually desirable that each such cord be coiled and tied into a hank before it is connected to the appliance for which it is intended, and therefore the customary prior practice has been to collect accumulations of finished cords at the lead forming machine and take them to a hanking machine to be coiled and tied. Such batchwise handling of the cords was obviously somewhat inefficient, but heretofore it was regarded as unavoidable because no fully automatic hanking machine has been available.
A commercially available semi-automatic hanking machine that has been rather widely used is disclosed in U.S. Pat. Nos. 3,480,219 and 3,480,220, both issued to H. F. Hanscom. The machine of those patents comprises a turntable that is rotatable on a vertical axis and has a pair of upright coiling posts spaced to opposite sides of its axis. An operator manually inserts one end portion of a lead or cord into a clip on the turntable and depresses a foot switch to start the turntable rotating, thus causing the cord to be wound around the coiling posts. After a pre-determined number of turns the turntable stops, whereupon an arm on another part of the machine moves down and removes the coiled cord from the posts. The arm has claws that engage the coil at spaced apart locations between the posts and close around it. The arm first moves straight up to lift the coil off of the coiling posts, and then it swings laterally to carry the coil to a tying machine by which a wire tie is looped around the middle of the coil and twisted upon itself. The claws thereafter open to release the tied hank into a receptacle or onto a conveyor. Once the coil has been lifted away from the coiling posts, the operator can attach a new cord to the turntable and start a new winding cycle, so that winding of one cord can take place while a previously wound coil is being tied and released from the arm.
It is apparent that the machine of the Hanscom patent can achieve high production with a diligent and patient operator. However, it is also apparent that feeding cords or leads to such a machine demands a certain amount of concentration and coordination on the part of the operator but is a very monotonous task and is therefore very fatiguing.
A problem encountered with any hanking machine is that during the coiling operation there is always a certain amount of cord that extends away from the turntable and is being wound in towards it. If that unwound portion of the cord is not guidingly confined, it can begin to swing around with the turntable instead of being wound into a coil. Such swinging can result in a defective hank with an excessively long pigtail, and it may also endanger nearby personnel. With a manually fed hanking machine the operator provides the necessary guidance for the uncoiled portion of the cord; but with a fully automatic machine, that part of the cord, while being confined against swinging, must nevertheless be free to move lengthwise towrds the turntable at whatever rate is imposed by the coiling operation.
The above-mentioned copending application of Gudmestad, et. al., Ser. No. 277,964, discloses a fully automatic hanking machine whereby a wire lead or other cord that has been discharged from a lead forming machine or the like is gripped near one of its ends, and while that grip is maintained the cord is horizontally extended and is presented to the coiling turntable with its gripped end in a known relationship to the turntable coiling posts. Grippers on the outer ends of the coiling posts close upon the cord near its gripped end, which is then released. The other end of the cord is slidably guided as it is being wound in towards the turntable. The mechanism for presenting cords to the coiling turntable is somewhat complicated, and further complications are involved in the grippers on the coiling posts and the mechanism for actuating them at appropriate times.
Although the automatic hanking machine of the copending application can be mounted adjacent to a lead forming machine to receive leads as they issue from it, and can coil and tie leads as quickly as they are produced, that hanking machine is mainly useful for special situations where it is not possible to take full advantage of the possibilities for cooperation between the lead forming machine and the hanking machine.